1. Field of the Invention
The present invention relates to test handlers. More particularly, the present invention relates to a technology that can be applied to carrier boards for loading semiconductor devices having a ball type of electrical contact lead (BGA, FBGA, etc.), in a pick-and-place apparatus for electronic device inspection equipment.
2. Description of the Related Art
Electronic devices such as, semiconductor devices are tested via a tester, when a test handler makes them electrically contact the tester.
Test handlers are closely related to technology involving electrical contact precision between electronic devices and the tester, temperature controllability, and an electronic device moving method. Of them, electrical contact precision is the most important factor. The present invention is related to how to guarantee electrical contact precision.
Semiconductor devices are electronic devices and their electrical contact leads are divided into a type of wire, for example, TSOP, SOP, TQFP, QFP, etc., and a type of ball, for example, BGA, FBGA, etc. It is very important that the electrical contact leads of the semiconductor device precisely contact the tester, irrespective of their type.
In particular, a semiconductor device having a ball type electrical contact lead exquisitely aligns a plurality of electrical contact leads on its underside, so the electrical contact leads may not electrically contact the tester if the semiconductor device is even slightly misaligned.
In general, test handlers transfer semiconductor devices via a carrier board (also called a test tray, a test board, or the like) and also allow the semiconductor devices loaded on the carrier board to electrically contact the tester.
A carrier board includes a plurality of inserts (also called a carrier, a carrier module, etc.) aligned in a matrix form. An insert loads one or more semiconductor devices thereon. A technology related to a carrier board and an insert was disclosed in Korean Patent Publication No. 10-2005-0009066 entitled “carrier module for semiconductor device test handlers,” which is hereinafter referred to as a “well-known technology.” This publication discloses the insert in which a BGA chip can be properly placed.
FIG. 1 is a view illustrating a conventional insert that loads semiconductor devices with BGA type electrical contact leads.
Referring to FIG. 1, the conventional insert forms a placement compartment 111 that corresponds in size to a semiconductor device in a loaded part 110 on which a semiconductor device is loaded. The bottom side of the placement compartment 111 is perforated so that the ball type of electrical contact leads of the placed semiconductor device can be electrically contacted with the tester.
In addition, the placement compartment 111 also forms grooves, corresponding to the shape and spacing of the balls of the semiconductor device, on the inner wall of the perforated bottom side thereof.
When a semiconductor device is appropriately placed in the placement compartment, the balls of the semiconductor device are inserted into the grooves of the placement compartment, so that the semiconductor device can be stably loaded on the loaded part 110.
Meanwhile, since the semiconductor devices loaded in the carrier board are electrically contacted with a tester, the test handler is equipped with a pick-and-place apparatus that can load semiconductor devices from a customer tray onto a carrier board or unload semiconductor devices from a carrier board onto a customer tray.
The pick-and-place apparatus includes a plurality of picking apparatuses each of which can pick and place one semiconductor device.
In general, a picking apparatus includes a picker that sucks and picks a semiconductor device according to vacuum pressure or places it by releasing the vacuum pressure.
The following description describes the transfer and loading methods of semiconductor devices in a conventional picking apparatus.
The picking apparatus sucks and picks semiconductor devices from a loading element A (which may be a customer tray, a buffer, an aligner, a carrier board, etc.) and is then moved up over a loading element B (which may be a customer tray, a buffer, an aligner, a carrier board, etc.). When the pick-and-place apparatus moves, the picking apparatuses are also moved. The pick-and-place apparatus is lowered a certain distance above the loading element B and then places the semiconductor devices thereon, so that the semiconductor devices can be dropped and loaded on the loading element B.
However, semiconductor devices with a ball type of electrical contact leads have a relatively narrow spacing between their electrical contact leads, so they can be easily misaligned in the carrier board due to an impact when the semiconductor devices are dropped or an impact accompanying an operation where the apparatuses hold the semiconductor devices. In that case, the semiconductor devices cannot be electrically contacted with the tester, which causes test failure.